It feels like Chinese windmills with backdoor controls from the Chinese government is both a crazy idea and pretty easily solved. Just rip out and replace whatever remote control system is in it. Unless it's wired to a bomb, worst case scenario they shut it down while you manually restart them.
Grid tie equipment has to be carefully controlled to not cause worse problems down the line, but it only takes experienced and knowledgeable controls engineers to work out what programming is needed and make/install a system to do that. It's not something completely impossible or something only the Chinese can do.
Its all cloud connected shitware yeah. If you rip out the spyware it will stop working or wont spit out any monitoring data.
The same with chinese grid tie solar inverters btw. You can disconnect those from the internet but consumers dont do that because they want the cloud monitoring and have no clue.99% of people dont know how to make a custom influxdb + grafana setup.
even if somehow these windmills need regular maintenance by Chinese operators, there's still an easy solution: 1. put all the management endpoints into an isolated network where they can be accessed from a jumpbox; 2. provide access under escort, so German proctors are monitoring the session and can pause it at any time. extremely noncredible!